Using flake8 to tidy up a file

You have just written a module for calculating the absolute value of a given number. It's passing all your tests, but you are concerned that it does not conform to proper style guidelines. Sticking to style guidelines means your users, collaborators, and you, will be able to read and understand your code more easily.

As the Zen of Python states,

Readability counts.

In this exercise, you will use flake8 to point out style violations and fix them.